Phyllachora huberi P. Henn

Distribution

The 1998 Survey shows that the disease is severe in Brazil and Guyane.

Symptoms

The symptoms appear only in mature leaflets. In the beginning on the lower surface of the leaflets appear chlorotic lesion forming later on shiny black mass of stromats. The stromatas may be displayed in concentric circules separated by areas of leaf tissue. On the upper surface of the leaflets, the portions of tissue corresponding to each crust, the epiderm shows a little yellow, forming a round chlorotic spot. Chlorotic areas develop around the crusts becoming necrotic, when secondary fungi invasion occurs.

Together with stromatas of P. huberi there may be stromatas of Rosenscheldiella heveae. The crusts of P. huberi and of R. heveae are parasited by Dicyma pulvinata forming a white-gray mass and by Cylindrosporium concentricum forming a compact mass of micelium and cream esporulation.

Disease control

The black crust control, may be done with only two sprays of benomy (0,5g/z) or of thiophanate methy (1,0g/z).